The US army is used by various 'interests' as a kind of empire 'towing' service. When the money lenders who lend money to entire nations want to get their money back, they can't go and 'tow away' the nations as they would do with a car for which the loan isn't being paid - so they use the US military for that role.

There is also an entire network of paranoid and emotionally dysfunctional people running the military, which furthers the agenda of those who want to use it to spy on and control everyone else.